Problems frequently occur when transporting a support rail, mounting electrical components onto a support rail and/or finishing electrical components already arranged on the support rail, for example by attaching marker labels, before the support rail is positioned in a control cabinet. Semi-automatic or even fully automatic solutions are not standard or are not yet known. One reason for this is the extremely divergent contour of assembled support rails due to the very wide range of electrical components to be placed on them as well as a partly undefined shape of the support rails, which increases as the length increases. In particular, support rails are frequently bent or twisted. These properties prevent defined handling or guiding of the support rails whilst components are being mounted on them and thus an accurately reproducible and precise positioning and/or finishing of the electrical components on the support rail.